Grid leak



Nov. l23 1926.

w. B. scHoEPPLl-:R

GRID LEAK Filed June v5, 1924 YM TTG-i7 Y Fig.

Patented Nov. 23, 1926.

UNITED STATES WALTER B. SGHO-EPPLER, F NEW YORK, N. Y.

VGRID Laax.

Application filed AJune 3,

vision of a novel and improved form of grid leak which is of simple construction and can be manufactured at small cost.

For v*further comprehension of the invention, and of the objects and advantages thereof, referencewill be had to the following description and accompanying drawing,

i -glidto the ap ended claims in which the 4l"variatie novel eatures of the invention are mere particularly set forth.

. Fi l ofthe drawing is a longitudinal sectiona -view showing my improved grid leak. Fig. 2 is a transverse sectional view taken on the line 2-2 of Fig. 1.

Fi 3 is a like view taken on the line 3-3 of Fig. 1.

Fig. 4 is a detail perspective view of one of the contact clips.

F ig. 5 is a like view of one of the end caps.

' -Fim 6 is a longitudinal sectional view 3 0 showin a. modified construction.

gis a like view to Fig. 6 and showing a further modification. Fig. 8 is a modified arrangement o -`the clip, and cap in which the clip retai the cainplace. Y eferring noar to the drawing, my im'- proved grld leak comprises aninsulating tube or casing 10 which is preferably made ,of glass, this tube being formed with both endsopen for insertion of the resistance elevments, these ends being afterward closed by Suitable ca s, or ferrules. The resistance element whlch I make use of comprises a. Strip 12 of paper which is impregnated with a suitable chemical preparation to give it the required resistance, and which may Vbe of a width to extend about onequarter way aroundthe tube, although the width may be varied, or arranged as desired to suit different conditions. The paper is of substantialu lythe saine length as the tube, being here shown as slightly shorter, and is inserted in the tube in Contact with the inner surface thereof.l This paper "is engaged, adjaeentopposite ends thereof, by contact clips 15 which are 1am. semaine. 717,462.

made of copper or other metal strips and.

J'which comprise an inner portion engaeing in the tube and laterally expanded to' ear on opposite'sides of the tube, and an outerU portion which straddles th`e end `of the tube wall. To form this expanded' portion the clips are preferably bent, as seen in side @elevation, to a V-form as at 15 the apex of this V-portion bearing on one side of the tube, while the inner end of the clip bears on. the paper as shown, the intermediate portion of the clip bearing on the side of the glass tube diametrically opposite to'that against which the apex of the- V-portion bears. The outer end portion of the clipI is bent backwardly .over the body of the clip as -at 15 and engages over the end of the tube 10, this end portion being preferably rounded as seen in 1 cross section in F ig. 3 of the drawing to it 75 snugly upon the tube. l The clips are held in place 4by meansA of the caps or ferrules 18 which are fitted over l the ends of the tube and which engage the turned back ends 15h' of the clips. As shown 80 clearly inFigrll of the drawing the turned back end of each clip s'inclined, from its root to its tip, in the direction of the body of the clip so that when the cap or ferrule ismounted on the tube it will bear in an in- .ward directionon the project-ing end of the clip and by such action tend to force the in.- ner end of the clip against the resistance strip 12, the apex of the V-part of the clip J acting as an abutment or fulcrum to transfer the inward pressure on the outer end of the clip topan outward pressure on the inner end of the clip, thereby binding', the latter more securely against the paper'strip 12. The caps or ferrules are preferably secured in place by means of a suitable cement.

In the form of the invention shown' in Fig. 6 ofthe drawing I make use of the tube 10, impregnated paper l2, clips l5 and ferrules. 18 as above described. In this case however, a cork disk 20 is inserted into the tube and positioned therein between the ends thereof, w while copper or other metal strips 21 extend from the clips to the said disk, these metal strips beingengaged by the linner ends of 105 the ,clips in the manner above `pointed out. The provision of these additional metal strips enables the deviceto be set to any riesired resistance.

In the form of the invention shown in Fig. 7 I make use of the tube 10 and paper 12. At one 4end of the tube I provide the clip15 .which bears on the paper and is secured in place as above set forth by thecap 18. To eo-operate wit-h the clip in engaging the paper Iy provide in thisV case an elongated metal strip which extends longitudinally through the tube and which is formed at its inner end With a V-portion 25 whereby it is `caused to bear at its end on the strip 12, the apex of the V-part 25 bearing on the diametrically opposite side of the tube.v The other endet` the tube is' Closed by a cap o'rferrule 18 which is formed with a 'suitable aperture -through which the strip 25 passes. After thest-rip has been adjusted With relation t0 the tube to produce the desired Ie-l thetube, While the Cap has aninturned lange 18c which engages behind a resilient hump 15d on the elip end. i

Having thus described my invention what I claim asnew and desire to protect by Letters Patent of the United States is -as follows f I p l. The combination Iin a grid leak having a tube, a resistance strip therein, and end caps, of a clip formed With an inner portion engaging in the tube, andy laterally expanded to bear on diametrically opposite sides of said-tube, and an outer portion which straddles the end of the tube Wall, said inner .porf tionbeing bent to a Vform, the apex of this V-portion bearing on one side of the tube, While the party opposite the apex bearing on the diametricallyopposite side of the tube against said Vresistance strip.

2. The combination in a grid leak having a tube, a resistance strip therein, and end caps, of a clip formed with an inner portion engaging in the tube, and laterally expanded to bear on diametrically opposite sides of said tube, and an outer. portion Which straddles the end of the tube Wall, said inner portion being bent to a V-form, the apex of this V-form bearing on one'side of the tube,`while the part opposite the apex bearing onthe diametrieally opposite side of the tube against said resistance strip, said outer portion beingclainpedv by' the said end caps, whereby the apex of the V-portion of the elip acts as a fulcrum' to transfer the inward pressure on the *outer end of the elipto an outward pressure on thew inner end of the clip.-

3. An electrical resistance element 'coinprising a tube, a resistaneej'striptherein, Aa substantially Vshapedclip bearing on said of said tube, a cap for securing said clip at'one end of said tube, a metal strip Within said tube extending through the opposite end thereof. a V-part formed with said metal strip adapted to bear on said resistance strip,

the 'apex of said V-part bearing on the diametrieally opposite side of said tube, a cap or ferrule through which the extended end of said metal strip is guided and adapted to close the end of said tube through'which said metal stripextends.y

In testimony whereof I' have affixed my signature.

WALTER B. SCHOEPPLER.

lresistance strip and guided about the mouth y 

